Open Access Highly Accessed Research article

HCV genotype 1a shows a better virological response to antiviral therapy than HCV genotype 1b

Adriano M Pellicelli1*, Mario Romano2, Tommaso Stroffolini3, Ettore Mazzoni4, Fabrizio Mecenate5, Roberto Monarca6, Antonio Picardi7, Maria Elena Bonaventura8, Cristina Mastropietro9, Pascal Vignally10, Arnaldo Andreoli1, Massimo Marignani11, Cecilia D’Ambrosio1, Lucia Miglioresi1, Lorenzo Nosotti12, Olga Mitidieri13, Umberto Vespasiani Gentilucci7, Claudio Puoti13, Giuseppe Barbaro14, Angelo Barlattani15, Caterina Furlan3, Giorgio Barbarini16 and and for the CLEO Group

Author Affiliations

1 Liver Unit Azienda Ospedaliera San Camillo Forlanini, Circonvallazione Gianicolense, 87 00149, Rome, Italy

2 Liver Unit Ospedale Sandro Pertini, Via dei Monti Tiburtini 385, 00157, Rome, Italy

3 Department of Infectious and Tropical Disease Policlinico Umberto I, Viale del Policlinico 155, 00161, Rome, Italy

4 Liver Unit Policlinico Casilino, Via Casilina, 1049-00169, Rome, Italy

5 Liver Unit Ospedale Villa Betania, Via Niccolò Piccolomini 27, 00165, Rome, Italy

6 Infectious Disease Ospedale di Belcolle strada Sammartinese, 01100, Viterbo, Italy

7 Liver Unit Campus Biomedico University, Via Álvaro del Portillo, 21 00128, Rome, Italy

8 Infectious Disease Ospedale San Camillo de Lellis, Via John Fitzgerald Kennedy, 02100, Rieti, Italy

9 Department of Infectious Disease Policlinico Umberto I, Viale del Policlinico 155, 00161, Rome, Italy

10 National Institute of Health, Viale Regina Elena 299, 00161, Rome, Italy

11 Department of Digestive and Liver Disease, Azienda Ospedaliera Sant'Andrea, Via Grottarossa, 1035/1039, Rome, Italy

12 Medicine of Migration National Institute for Migrant Health and Poverty, Via di S. Gallicano 25/a, 00153, Rome, Italy

13 Department of Internal Medicine and liver unit Ospedale Generale di Marino, Viale XXIV Maggio, 00047, Marino Rome, Italy

14 Department of Medical Pathophysiology, University of Rome La Sapienza, Viale del Policlinico 155, 00161, Rome, Italy

15 Liver Unit ASL RM/A, Rome, Italy

16 Infectious and Parasitic Diseases, Policlinico San Matteo P.zzale Golgi,2, 27100, Pavia, Italy

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BMC Gastroenterology 2012, 12:162  doi:10.1186/1471-230X-12-162

Published: 16 November 2012



The impact of viral subtype on the rate of sustained virological response (SVR) to antiviral therapy in patients chronically infected with hepatitis C genotype 1 subtype 1a and 1b has not been extensively investigated. The aim of this study is to determine whether the HCV genotype 1 subtypes 1a and 1b respond differently to treatment with PEGylated interferon (PEG-IFN) plus ribavirin.


For 48 weeks, 388 “naïve”genotype 1 patients were treated weekly with PEG-IFN α-2a or PEG-INF α-2b combined with daily ribavirin (1000–1200 mg/day). The numbers of patients in whom HCV-RNA was undetectable were compared after 4 (rapid virological response, RVR), 12 (early virological response, EVR), and 48 (end treatment virological response, ETR) weeks of treatment as well as 24 weeks after the last treatment (sustained virological response, SVR).


The rate of SVR was higher in subtype 1a patients than subtype 1b patients (55% vs. 43%; p < 0.02). Multiple logistic regression analysis showed that infection with genotype 1a (odds ratio(OR) : 1.8; 95% confidence interval (CI): 1.4 to 4.1), age < 50 years (OR:7.0; 95% CI 1.1 to 21.2), alanine aminotransferase level (ALT)<100 IU/ml (OR:2.1; 95% CI: 1.3 to3.5), HCV-RNA < 5.6 log10 IU/ml (OR: 3.2; 95% CI: 2.7 to 6.9) and fibrosis score < S3 (OR: 3.8; 95% CI:3.2 to 7.4), were all independent predictors of SVR.


Dual antiviral therapy is more effective against HCV subtype 1a than against subtype 1b and this difference is independent of other factors that may favour viral clearance.

Trial registration Identifier: NCT01342003

Genotype 1a; HCV genotype 1 subtypes; Sustained virological response; Antiviral therapy; Pegylated interferon